Clinics in diagnostic imaging (194). SVC aneurysm.

A 68-year-old woman presented with weight loss of 7 kg over two years. Clinical examination revealed no specific abnormality and the patient was otherwise asymptomatic. Chest radiography performed to screen for malignancy revealed a soft tissue opacity projected over the mediastinum. Computed tomography of the thorax showed an enhancing anterior mediastinal mass with heterogeneous enhancement and contrast pooling in the arterial phase, followed by homogeneous enhancement in the venous phase, consistent with an aneurysm arising from the superior vena cava. This case highlights superior vena cava aneurysms as extremely rare causes of anterior mediastinal masses. Other causes of anterior mediastinal masses were also discussed.